Antisludging means for oil



April 10, 1928 D. C. COX

ANTISLUDGING MEANS FOR OIL Filed Sept. 28 1926 3 I 1- Cwl/w/is /Z///6/5 car/71 Inventor:

David (lcox,

H i s Att rn ey.

Patented Apr. 10, 1928.

UNITED STATES PATENT orrlcs.

DAVID C. COX, SOLDIER SUMMIT, UTAH, ASSIGNOR TO GENERAL ELECTRIC OOH- PANY, A CORPORATION OF NEW YORK.

ANTISLUDGING MEANS FOR OIL.

Application fled September 28, 1988. Serial No. 188,308.

The present invention relates to devices, such as transformers or capacitors, having a bath of mineral oil which is heated for long periods of time to an elevated temperature.

It is the object of my invention to increase the length of time that such a device may be operated with a given charge of oil.

When mineral oil isoperated at a high temperature for a protracted length of time,

to a semi-solid precipitate or sludge forms in the oil. This sludge appears to be an oxidation product and includes complex acids and other deleterious substances.

In accordance with my invention, the useful life of insulating oil is greatly extended by providing a charge of fullers earth in contact with the oil in an oil-containing apparatus.

One embodiment of my invention is illustrated by the accompanying drawing showing in side elevation a transformer, provided with a chargeof fullers earth, the tank wall being in part broken away. v

Referring to the drawing, the transformer comprises the usual standard parts, such as a 5 core 1 and windings 2 contained within a tank 3 and provided with the usual terminals 4, 5 and ground connectipn fi. ,}-These and accessory members have been shown merely as being illustrative of a transformer.-i-At 0 the bottom of the tank 3 and below the yoke 7 of the core is a wire mesh basket 8, supported on suitabl' insulated standards 9, 10, and containing t e'charge of fullers earth. The basket 8 may be lined with wire screen 5 of sufficient fineness to hold the granules ofearth. Although the amount of fullers earth may be varied greatly, I have found that about six ercent b volume of fullers I earth in the oiF to be e ective'in increasing 0 the useful life of the oil about two or three times. A larger percentage of fullers earth in the oil is even more effective but, of course,

a much larger bulk of fullers earth becomes cumbersome.

It is not essential that the fullers earth shall be located in a container or that it shall be located in any particular place in a transformer or similar device. The arrangement shown in the drawing is illustrative of one means for carr ing out my invention.

The action 0 absorber of potential sludge, n'amely,.prodnets of oxidation, which first appear as a discoloration in the oil. This coloring matter not only eventually would saturate the oil and then precipitate as a sludge, but it acts also as a catalyst for further oxidation.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In combination with a charge of mineral oil which is subjected to an elevated temperature for a sufficient length of time to permit sludging' to occur, a body of .fullers earth in contact with said oil, and suficient in quantity to reduce sludging of the oil.

2. In. an electrical device containing a charge of mineral oil, and operable at an elevated 'tem rature, the provision of a quantity of I llers earth in contact with In witness whereof, I have hereunto set my hand this th day of Se t. v1926.

\ DA C. COX.

. the fuller s earth in decreasmg sludging is not understood. It acts as an 

